1. Field of the Invention
The present invention relates to a method of processing a figure and a recorded medium. More particularly, the present invention relates to a method of processing a figure in which a mask pattern is subjected to a resizing processing which includes an enlarging processing and a reducing processing, when LSI (large-scale integrated package) is manufactured by means of CAD (Computer Aided Design).
2. Description of the Related Art
In the mask data conversion system in which CAD data of an LSI is converted into data for exposure (manufacture), sizing processing is provided, which is referred to as xe2x80x9cresizing processingxe2x80x9d in some cases, in which an outer circumference of figure P of a mask pattern (mask figure) is enlarged by a predetermined value (enlarging processing or plus sizing processing) and reduced (reducing or minus sizing processing), as shown in FIG. 7. This sizing processing is performed for the purpose of correction so that deformation caused in the manufacturing process can be corrected and also for the purpose of correction conducted according to a change in the designing rule.
Usually, in the data conversion system for converting mask pattern data in the case of manufacturing an LSI, in order to avoid carrying out complicated processing, mask pattern P composed of a polygon is divided into a plurality of horizontal trapezoids (trapezoids A and B, the upper sides and the lower sides of which are parallel with axis X) as shown in FIG. 8, and sizing processing and other various figure processing, such as AND, OR, XOR, NOT, SUB and so forth, are conducted on the basis of these horizontal trapezoids. In this connection, the concept of a xe2x80x9chorizontal trapezoidxe2x80x9d includes a figure, the length of the upper side or the lower side of which is zero, that is, the concept of a xe2x80x9chorizontal trapezoidxe2x80x9d includes a xe2x80x9ctrianglexe2x80x9d.
As shown in FIG . 9, it is assumed that the sizing processing, which is one of the aforementioned figure processing, is conducted and horizontal trapezoids A and B defining mask pattern P expressed by one polygon are individually resized. In the case of a reducing (minus) processing, concerning horizontal trapezoids Axe2x80x2 and Bxe2x80x2 which are adjacent to each other, the upper side of the reduced horizontal trapezoids Axe2x80x2 and the lower side of the reduced horizontal trapezoid Bxe2x80x2 are separated from each other, so that a slit is formed between the two horizontal trapezoids Axe2x80x2 and Bxe2x80x2. In the case of an enlarging (plus) processing, corners of horizontal trapezoids Axe2x80x2 and Bxe2x80x2, which have been enlarged, stick out from the regions of the adjacent horizontal trapezoids.
Therefore, according to the conventional resizing processing, the horizontal trapezoids defining one polygon are once composed into the polygon itself, and resizing processing is conducted on the polygon itself.
However, the efficiency is low in the case of the aforementioned processing in which the divided horizontal trapezoids are once composed into a polygon each time of sizing processing and then new horizontals trapezoids are formed after the completion of sizing processing.
The present invention has been accomplished to solve the above problems. It is an object of the present invention to provide a method of processing a figure capable of conducting a resizing processing on a mask pattern expressed by a set of horizontal trapezoids without once composing the horizontal trapezoids into a polygon.
In order to solve the above problems, the present invention provides a method of processing a figure for obtaining an enlarged, figure or a reduced figure by moving the sides of a polygon, which is composed by putting a plurality of horizontal trapezoids upon each other, each of the trapezoids having upper and lower sides parallel to X-axis, in the direction of Y-axis to the outside or inside of the polygon in parallel with each other,
the method of processing a figure comprising the steps of:
selecting the horizontal trapezoid one by one along Y-axis out of the plurality of horizontal trapezoids as an objective horizontal trapezoid;
extracting a first group of segments included in the sides composing the objective horizontal trapezoid and also composing the sides of the polygon, also extracting a second group of segments included in an upper side and right and left sides of a lower horizontal trapezoid and composing the sides of the polygon if there is such a lower horizontal trapezoid coming into contact with the lower side of the objective horizontal trapezoid, also extracting a third group of segments included in the side of an upper horizontal trapezoid which is a side coming into contact with the objective horizontal trapezoid and composing the sides of the polygon if there is such an upper horizontal trapezoid coming into contact with an upper side of the objective horizontal trapezoid;
creating a new first group of segments, a new second group of segments and a new third group of segments, if the first group of segments, the second group of segments and the third group of segments are respectively moved to the outside or inside of the polygon in parallel with each other and also if an extension line located outside the polygon or a segment after the completion of movement is removed on the basis of an intersection point of the extension line of the segment composing each group of segments which has been moved in parallel or on the basis of an intersection point of the segment composing each group of segments which has been moved in parallel;
removing the new third group of segments after the intersection point of the new first group of segments and the new second group of segments and the intersection point of the new first group of segments and the new third group of segments are stored as contact points and also removing the new second group of segments on the lower side of a division point if the predetermined division point exists on the new second group of segments;
sorting the contact point and the division point in the order of the Y coordinate value and the X coordinate value under the condition that priority is given to Y coordinate value;
drawing parallel lines parallel to X-axis from the contact point and the division point, in the order of sorting, to the inside of the polygon while it is being detected whether or not points of intersection exist between the new second group of segments and the parallel line or between the new first group of segments and the parallel line and also making a horizontal trapezoid encircled by the parallel line, the new first group of segments and the new second group of segments to be a new horizontal trapezoid composing the enlarged figure or the reduced figure if the points of intersection exist; and
storing the contact point and the point of intersection included in the parallel line, the Y-coordinate value of which is the highest in the parallel line on which the point of intersection exists, instead, of the division point if the upper horizontal trapezoid exists.
According to the method of processing a figure of the present invention, a mask pattern, which is a polygon expressed by a set of horizontal trapezoids, can be subjected to resizing processing without once synthesizing the horizontal trapezoids into a polygon. Therefore, it is unnecessary to conduct such processing that the horizontal trapezoids are once synthesized into a polygon each time of the processing of resizing and they are formed into new horizontal trapezoids after the completion of the processing of resizing. Accordingly, the process of resizing can be effectively carried out.